/Engine/Source/Runtime/Core/Public/Async/TaskGraphInterfaces.h
A (slow) function to call a function on every known thread, both named and workers
static void BroadcastSlow_OnlyUseForSpecialPurposes ( bool bDoTaskThreads, bool bDoBackgroundThreads, [TFunction](API\Runtime\Core\GenericPlatform\TFunction)< void([ENamedThreads::Type](API\Runtime\Core\Async\ENamedThreads__Type) CurrentThread)> & Callback )